1. Field of the Invention
The present invention relates to an apparatus for reversing a sheet of paper and supplying the reversed paper to a printing unit to print both sides of the paper.
2. Description of the Related Art
In a typical printer or a copying machine for double-sided printing, an apparatus for reversing a sheet of paper and supplying the reversed paper to a printing unit in sequence is provided in order to print an image on both sides of the supplied paper.
As shown in FIG. 1, a conventional paper reversing apparatus includes forward-directional transfer rollers 40 which transfer a paper supplied from a paper cassette 20 or a manual feed tray 30 toward an output roller 60 via a printing unit 10, and reverse-directional transfer rollers 50 transferring the paper of the output roller 60 in the reverse direction, reversing the transferred paper, and again supplying the reversed paper to the printing unit 10.
In a printing process, a sheet of paper is supplied from the paper cassette 20 or the manual feed tray 30 and passed through the printing unit 10 for printing an image on one side of the paper. After one side of the paper is completely printed, the paper is caught by the output roller 60. The output roller 60 reversely rotates to resupply the paper, having one side already printed, by the reverse-directional transfer roller 50 to the printing unit 10 along a route indicated by the dotted lines in FIG. 1. At this time, the paper proceeds in the reverse direction to enter the printing unit 10 while the upper and lower side surfaces are reversed. As a result, an image can be printed on the other side of the paper. After both sides of the paper are completely printed, the paper is transferred by the forward-directional transfer roller 40 and is output by the output roller 60 to an output tray 70.
However, the conventional apparatus suffers from the disadvantage that the printer must be large in order to accommodate the conventional paper reversing apparatus since the paper must be transferred forwardly and reversely along a long route inside the printer.